The present invention relates to a curable polymeric composition or, more particularly, to a curable polymeric composition of a novel type useful as a potting agent, adhesive, coating material and the like formulated with an alkenyloxysilyl-containing organic polymer as the base ingredient as well as a cured rubbery elastomer obtained therefrom.
In the chemistry and industry of organosilicon compounds, alkenyloxysilyl-containing compounds such as the organosilane compounds represented by the general formula EQU R1.sub.4-n Si(O--CR.sup.3 .dbd.CH--R.sup.2).sub.n,
in which R.sup.1 is a monovalent hydrocarbon group, R.sup.2 and R.sup.3 are each hydrogen atom or a monovalent hydrocarbon group and n is a positive integer of 1, 2 or 3, including, typically, methyl triisopropenyloxy silane, are well known and useful as an important ingredient in many silicone compositions. For example, methyltriisopropenyloxy silane is useful as a crosslinking agent in a room temperature-curable organopolysiloxane composition utilizing the reactivity of the isopropenyloxy groups with water in the presence of a curing catalyst, such as amine compounds, carboxylates of heavy metals and the like, to produce acetone as a condensation by-product and forming a siloxane linkage (see, for example, Japanese Patent Publication No. 51-39673). Room temperature-curable organopolysiloxane compositions curable by this mechanism are very advantageous in respect of the high heat resistance and absence of corrosiveness so that they are widely used as a heat-resistant material for insulating sealing of various kinds of electronic components and as a sealing material in and around automobile engines.
It is also know that the alkenyloxy-containing organosilicon compounds or, in particular, isopropenyloxy-containing organosilicon compounds are susceptible to photochemically induced addition reaction with a mercapto group-containing organosilicon compound under irradiation with ultraviolet light in the presence of a photosensitizer. This principle is utilized in several photocurable organopolysiloxane compositions.
In addition to the above described mechanisms of reactions, it is known that alkenyloxy silyl groups can participate in the so-called hydosilation reaction with silicon-bonded hydrogen atoms or hydrosilyl groups in the presence of a platinum catalyst. This principle is utilized in the present invention for the curing reaction of an organic polymer.